Biomonitoring - Phthalates

Indicators
About the Phthalates Indicators
Methods
Supplemental Data Tables
Related Links

Indicators

Phthalate metabolites in women ages 16 to 49 years: Median concentrations in urine, 1999-2018 (Indicator B9)

Web update: 2023

Click to open in new window | Tips for selecting and filtering data (pdf) (455.91 KB) | Download in Excel

Data characterization

Data for this indicator are obtained from an ongoing continuous survey conducted by the National Center for Health Statistics.
Survey data are representative of the U.S. civilian noninstitutionalized population.
Phthalate metabolites are measured in urine samples obtained from individual survey participants.

From 2001-2002 to 2007-2008, the median level of DEHP metabolites in urine of women ages 16 to 49 years varied between 42 µg/L and 51 µg/L, and was 51 µg/L in 2007-2008. The median level of DEHP metabolites decreased to 9 µg/L in 2017-2018. There was a statistically significant trend in median DEHP metabolites over 2007-2008 to 2017-2018.
From 1999-2000 to 2007-2008, the median level of DBP metabolites in urine of women ages 16 to 49 years varied between 27 µg/L and 36 µg/L, and was 36 µg/L in 2007-2008. The median level of DBP metabolites decreased to 21 µg/L in 2017-2018. There was a statistically significant trend in median DBP metabolites over 2007-2008 to 2017-2018.
From 1999-2000 to 2007-2008, the median level of BBzP metabolites in urine of women ages 16 to 49 years varied between 10 µg/L and 14 µg/L, and was 12 µg/L in 2007-2008. The median level of BBzP metabolite decreased to 3 µg/L in 2017-2018. There was a statistically significant trend in median BBzP metabolite over 2007-2008 to 2017-2018.
For the years 2015-2018, Black non-Hispanic women of child-bearing age had higher median concentrations of all the phthalate metabolites shown here compared with White non-Hispanic women, and women of “All Other Races/Ethnicities.” These differences were all statistically significant. (See Indicator B9a.)
Median levels of urinary phthalate metabolites varied by family income. For the years 2015-2018, women living below poverty level had higher concentrations of phthalate metabolites in their urine compared with women living at or above poverty level. These differences between income groups were statistically significant for all the metabolites, after adjusting for age and race/ethnicity. (See Indicator B9b.)
From 2001-2002 to 2007-2008, the concentration of DEHP metabolites in the 95th percentile varied between 462 µg/L and 578 µg/L, and was 567 µg/L in 2007-2008. There was an increasing trend in the 95th percentile concentration of DBP metabolites in women of child-bearing age, from 128 µg/L in 2001-2002 to 160 µg/L in 2007-2008. From 1999-2000 to 2007-2008, the 95th percentile concentration of BBzP metabolite varied between 68 µg/L and 100 µg/L, and was 71 µg/L in 2007-2008. The increasing trend for DBP metabolites at the 95th percentile from 1999-2000 to 2007-2008 was statistically significant after accounting for differences by age, race/ethnicity, and income. (See Table B9d.)
From 2007-2008 to 2017-2018, the 95th percentile concentration of DEHP metabolites decreased from 567 µg/L to 40 µg/L, the 95th percentile concentration of DBP metabolites decreased from 160 µg/L to 77 µg/L, and the 95th percentile concentration of BBzP metabolite decreased from 71 µg/L to 30 µg/L. These decreasing trends were all statistically significant, after adjusting for differences in age, race/ethnicity, and income. (See Table B9d.)

Phthalate metabolites in children ages 6 to 17 years: Median concentrations in urine, 1999-2018 (Indicator B10)

Web update: 2023

Click to open in new window | Tips for selecting and filtering data (pdf) (455.91 KB) | Download in Excel

Data characterization

Data for this indicator are obtained from an ongoing continuous survey conducted by the Centers for Disease Control and Prevention’s National Center for Health Statistics.
Survey data are representative of the U.S. civilian non-institutionalized population.
Phthalate metabolites are measured in urine samples obtained from individual survey participants.

From 2001-2002 to 2007-2008, the median level of DEHP metabolites in urine of children ages 6 to 17 years varied between 45 µg/L and 62 µg/L, and was 45 µg/L in 2007-2008. From 2007-2008 to 2017-2018, the median level of DEHP metabolites in urine of children ages 6 to 17 years decreased to 13 µg/L. There was a statistically significant trend in median DEHP metabolites over 2007-2008 to 2017-2018.
From 1999-2000 to 2007-2008, the median level of DBP metabolites in urine of children ages 6 to 17 years varied between 36 µg/L and 42 µg/L, and was 41 µg/L in 2007-2008. From 2007-2008 to 2013-2014, the median level of DBP metabolites in urine of children ages 6 to 17 years decreased to 25 µg/L, increased to 28 µg/L in 2015-2016, and decreased to 25 µg/L in 2017-2018. There was a statistically significant trend in median DBP metabolites over 2007-2008 to 2017-2018.
The median level of BBzP metabolite in urine of children ages 6 to 17 years decreased from 25 µg/L in 1999-2000 to less than 8 µg/L in 2013-2014, increased slightly to just over 8 µg/L in 2015-2016, and then decreased to 5 µg/L in 2017-2018. This decreasing trend was statistically significant.
For the years 2015-2018, Black children ages 6 to 17 years had higher median concentrations of all phthalate metabolites compared with White non-Hispanic children, All Hispanic children, Mexican-American children, and children of “All Other Races/Ethnicities.” These differences were all statistically significant. (See Indicator B10a.)
For the years 2015-2018, children ages 6 to 17 years living below the poverty level had higher median concentrations of all the phthalate metabolites detected in their urine compared with children living at or above the poverty level. These differences were all statistically significant after accounting for differences in age and income. (See Indicator B10b.)
At the 95th percentile, there was an increasing trend in the concentration of DEHP metabolites in children ages 6 to 17 years, from 387 µg/L in 2001-2002 to 564 µg/L in 2007-2008. From 1999-2000 to 2007-2008, the concentration of DBP metabolites varied between 166 µg/L and 191 µg/L, and was 191 µg/L in 2007-2008. From 1999-2000 to 2007-2008, the concentration of BBzP metabolite varied between 104 µg/L and 151 µg/L, and was 107 µg/L in 2007-2008. The increasing trend for DEHP metabolites from 2001-2002 to 2007-2008 was statistically significant. (See Table B10d.)
From 2007-2008 to 2017-2018, the 95th percentile concentration of DEHP metabolites in children ages 6 to 17 years decreased from 564 µg/L to 59 µg/L, the 95th percentile concentration of DBP metabolites decreased from 191 µg/L to 98 µg/L, and the 95th percentile concentration of BBzP metabolite decreased from 107 µg/L to 35 µg/L. These decreasing trends were statistically significant for DEHP, DBP and BBzP, after accounting for differences in age, sex, race/ethnicity, and income. (See Table B10d.)
For the years 2015-2018, children ages 6 to 10 years had higher median levels of phthalate metabolites in their urine compared to adolescents ages 16-17 years. The age group differences were statistically significant for DEHP and BBzP, but not for DBP, after accounting for differences in sex, race/ethnicity, and income. (See Table B10e.)

About the Phthalates Indicators

Indicators B9 and B10 present information about phthalate metabolite levels measured in women and children. The data are from a national survey that collects urine specimens from a representative sample of the population every two years, and then measures the concentration of various contaminants in urine. These indicators focus on both women of child-bearing age and children because of concern for potential adverse effects in children born to women who have been exposed to phthalates and in children exposed to phthalates.

Indicator B9 presents concentrations of phthalate metabolites in urine of women ages 16 to 49 years from 1999-2018.
Indicator B10 presents concentrations of phthalate metabolites in urine of children ages 6 to 17 years from 1999-2018.

Phthalates are a class of manufactured chemicals commonly used to increase the flexibility of plastics in a wide array of consumer products. By far the most common use of phthalates is in the production of polyvinyl chloride (PVC) products—PVC is the second most commonly used plastic in the world, and is present in pipes and tubing, construction materials, packaging, electrical wiring, and thousands of consumer goods. Phthalates may be found in wall coverings, tablecloths, floor tiles, furniture upholstery, pesticides, some toys, automobile upholstery, food packaging, cosmetics, hair and skin care products, and some medications. Phthalates are not strongly bound in these products and can therefore leach out. The major route of human exposure to most phthalates is food ingestion; other routes of exposure include inhalation, drinking contaminated water, and absorption through the skin.

Some phthalates are suspected endocrine disruptors. Endocrine disruptors act by interfering with the biosynthesis, secretion, action, or metabolism of naturally occurring hormones. Given the importance of hormones in human physiology, there is concern in the scientific community over the potential for endocrine disruptors to adversely affect children’s health, particularly in reproduction, development, and behavior. Male laboratory animals exposed to high doses of some phthalates have been known to display elements of “phthalate syndrome,” which includes infertility, decreased sperm count, and changes to reproductive organs. These findings in animal studies, although typically occurring at exposure levels much higher than what the general population may be exposed to, suggest a potential concern for health effects in children as well. The National Research Council has concluded that prenatal exposure to certain phthalates produces reproductive tract abnormalities in male rats, and also concluded that the same effects could plausibly occur in humans.

Indicators B9 and B10 present phthalate metabolite levels measured in urine of women and children from the National Health and Nutrition Examination Survey (NHANES). Data are presented for three important phthalates: di-2-ethylhexyl phthalate (DEHP), dibutyl phthalate (di-n-butyl phthalate and di-isobutyl phthalate) (DBP), and butyl benzyl phthalate (BBzP).

More information about phthalates and Indicators B9 and B10 is provided in the Phthalates section of America's Children and the Environment, Third Edition (pdf) (1015.7 KB) .

Methods - Phthalates

The National Center for Health Statistics, a division of the Centers for Disease Control and Prevention, conducts the National Health and Nutrition Examination Surveys (NHANES), a series of U.S. national surveys of the health and nutrition status of the non-institutionalized civilian population. Interviews and physical examinations are conducted with approximately 10,000 people in each two-year survey cycle. The survey measures phthalate metabolite levels in urine samples collected from NHANES participants. The three phthalate metabolites analyzed are mono-n-butyl phthalate (MBP), mono-benzyl phthalate (MBzP), and the sum of the three metabolites mono-2-ethylhexyl phthalate (MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP).

Indicator B9 uses the NHANES data to present median concentrations of phthalate metabolites measured in urine of women ages 16 to 49 years. Indicator B10 uses the NHANES data to present median concentrations of phthalate metabolites measured in urine of children ages 6 to 17 years.